Field of the Invention
The invention relates to agricultural tools and more particularly tools comprising mainly one or more wheels.
In tools of this type, the wheel(s) is/are generally used to work the soil. The wheels may operate alone or in conjunction with other portions of the tool.
In the case of a sowing machine, for example, the tool comprises a portion which is provided to open a furrow in the soil, typically a ploughshare, a disc or a tooth, and one or more wheel(s) in order to close the furrow and/or to pack the earth after the seeds have been deposited at the bottom of the furrow.
Some tools, such as the above-mentioned sowing machine, also comprise so-called “depth control” wheels which control the working depth of the remainder of the tool. In the case of a tool comprising a ploughshare, for example, depth control wheels are mounted so as to be fixedly joined to the ploughshare so that, whilst travelling over the ground, the wheels retain the active portion of the ploughshare at a substantially constant depth.
Most often, the wheels with which agricultural tools are provided are intended to travel on the ground. They thus comprise a tire which is mounted around a portion of the wheel which forms the body thereof.
In order to prevent the tire from becoming disconnected from the wheel body during work, the portion of the wheel body which forms the rim is formed in a particular manner. This results in generally complex forms which complicate the production of the wheel body and also the mounting of the tire thereon.
That is the reason for which the wheels often comprise two similar flanges which are mounted one on the other in order to form the body of the wheel. The flanges are assembled one on the other by means of one of the main faces thereof, with the tire being enclosed.
Description of Related Art
In FR 2933903, the Applicant proposed an innovative wheel, whose shape of the wheel body prevents the tire from becoming detached from the rim during operation, including under extreme conditions. The body in question is formed by the mutual assembly of two similar flanges in a state face to face.
When they are used as tools, the wheels are generally subjected to great loads during operation.
In some cases, in particular when a sowing machine is provided therewith, the orientation of the wheel in the machine does not correspond to the advance direction of the machine: it is often the case that the wheel is inclined to a great extent in relation to the advance direction. Furthermore, the wheel may be inclined in relation to the vertical relative to the ground. During operation, this results in very great stress on the wheel body.
In order to ensure the rotation of the wheel about an axle, the occurrences of friction between the hub and the axle must be reduced, for example, by a bearing being received in the wheel body. The Applicant has established that the insertion of the wheel body around an axle and/or the insertion of a bearing into the hub may be difficult or become impossible during use of the wheel. That risk is all the greater if the adjustment of the hub in relation to the axle and/or the bearing in relation to the hub is particularly precise and the tolerances are small. That risk is aggravated when the operating conditions are severe and the stress undergone are great, as in the case of the sowing machine described above.
An objective of the Applicant is to improve the situation.